A typical gas-liquid contact apparatus generally comprises a column or tower containing a plurality of substantially horizontal trays arranged one above the other. In such an apparatus the gas or vapor passes successively through chimneys or tubes from one tray to another of the column or tower, and bubbles through a plurality of pools or streams of liquid on each tray. The gas or vapor is supplied at the bottom of the tower and discharged at the top thereof, and the liquid is supplied at the top and discharged at the bottom of the tower. In some petrochemical applications the respective flows are reversed.
In counterflow operation in which gas is taken off the top and liquid off the bottom, any constituents in the gas which are condensed by contact with the liquid escape with the latter at the bottom of the tower, while any remaining unabsorbed or uncondensed gas is drawn off from the top of the tower.
In such apparatus, it is customary to provide bubble cap assemblies which are mounted in fluid communication with openings provided on each tray of the gas-liquid contact apparatus. For economy of manufacture and standardization of parts, bubble cap assemblies in any one installation are usually of the same size and design. In a conventional installation the number and size of the bubble cap assemblies determines the total passage area for upward flow of gas from the space below a particular tray to the space above it.
After a period of time, the parts forming the bubble cap assembly may become corroded or coke-like deposits may form up on it. When the extent of corrosion or buildup of deposits reduces the efficiency of the contact apparatus below an acceptable limit, the operation of the tower is suspended for cleaning and repairs. Corrosion and deposits on the exposed surfaces of the bubble cap assemblies make it undesirable or impossible to effect any unthreadening of parts for the purpose of disassembly. Further, the arrangement of the parts on the tray is such that one person has access only to one end of the assembly for its installation or removal.
Accordingly, it would be advantageous to have a bubble cap assembly which could be installed by one person from one side of the tray, require no special tools for installation or removal, and would not include any parts that could fall through the opening in the tray from one level to the level below.